Alternating presser foot attachment

ABSTRACT

Top-feed attachment means for a drop-feed sewing machine having a lift pressure foot, said attachment means comprising a vibrating presser moveable relatively to the movement of the presser foot by operation of the needle bar into and out of engagement with a plurality of superimposed workpieces being fed to the machine, so that the workpieces will be moved simultaneously through the machine during a sewing operation.

United States Patent [72] inventor Edward L. Seaman 65 Harvard St., Garden City, N.Y. 11530 [21] Appl. No. 756,141 [22} Filed Aug. 29, 1968 [45] Patented Jan. 5, 1971 [54] ALTERNATING PRESSER FOOT ATTACHMENT 2 Claims, 8 Drawing Figs.

[52] 11.8. CI... 112/212 [51] Int. Cl D05b 27/04 [50] Field ofSearch 112/212, 207

[56] References Cited UNITED STATES PATENTS 1,474,966 11/1923 Hayes 112/212 2,474,282 6/1949 Sailer 112/212 Primary Examiner-Richard .l. Scanlan. Jr.

Attorneys-Abraham Engel, Robert S. Dunham, Pern E.

Henninger, Lester W. Clark, Gerald W. Griffin, Thomas F. Moran, Howard 1. Churchill, R. Bradlee Boal and Christopher C. Dunham ABSTRACT: Top-feed attachment means for a drop-feed sewing machine having a lift pressure foot, said attachment means comprising a vibrating presser moveable relatively to the movement of the presser foot by operation of the needle bar into and out of engagement with a plurality of superimposed workpieces being fed to the machine, so that the workpieces will be moved simultaneously through the machine during a sewing operation.

PATENTEDJAN 5197i 8552,5339

SHEET 1 OF 3 Z 34 L. f

INVENTOR. fDWARD Z, Sti l/WAN I Ar d A/EV PATENTEDJAN 5m 3.552.339

SHEET 2 [IF 3 I INVENTOR am/P0 Z, SEA/MN BY Arr-0 ME? PATENTED JAN 5 {97! SHEEI 3 [IF 3 INVENTOR. EDWARD A, SEAMAN ALTERNATING PRESSER FOOT ATTACHMENT The invention relates to top feed attachment means for a drop-feed sewing machine to insure the simultaneous feeding of a plurality of superimposed plies of material while being sewed together.

In feeding multiple assemblies comprising one or more synthetic fabrics which are smoother than conventional materials in a conventional drop-feed sewing machine, there is a great tendency toward puckering of the seam and the operator must continuously, or at least frequently, augment the mechanical feed of the machine with a manual feed. This is required because the feed dog contacts only the bottom one of the layers or workpieces of the assembly thus allowing the upper layers to slip behind the lower or driven layer.

Various mechanisms have been incorporated into such machines to overcome the foregoing difficulty. Attachments to conventional drop-feed sewing machines have also been provided for such purpose. Where these mechanisms are incorporated in a sewing machine they substantially increase the cost of the machine. Where such attachments'are added to a conventional sewing machine, they'have met with varying degrees of success.

Accordingly, it is an object of the present invention to provide a relatively simple attachment means to a conventional drop-feed sewing machine which will improve the speed, quality and ease of sewing superimposed workpieces.

A further object of the invention is to provide an attachment means for a drop-feed sewing machine which will eliminate puckering and thereby render the operators hand free to more easily, accurately, and efficiently guide the work through the machine.

The foregoing and other objects of the invention, not specifically enumerated, will become apparent from the detailed description which follows when considered in connection with the accompanying drawing showing a preferred embodiment and wherein:

FIG. 1 is a front elevation of the left end of the head of a conventional drop-feed sewing machine having the top feed attachment of the present invention mounted thereon;

FIG. la is a section taken along the line la-la of FIG. 1;

FIG. 2 is a section taken along the line 2-2 of FIG. 1;

FIG. 3 is an end elevation as viewed from the plane of the arrows 3-3 of FIG. 1;

FIG. 4 is an elevation as viewed from the plane of the arrows 4-4 ofFIG. 1; and

- FIGS. 5, 6 and 7 are fractional elevations corresponding to shown at 58a.

with the high point of the cam. I

die is in its upper positioii thelcarn :l lower is in engagement Pivotally mounted on a screw 56 which maybe coaxial with screw 48 but extending through the face 40 of the support member 36 to move over said face is an angular lever 58 which at its top forward end has an angular rounded shoulder 59 and at its forward end pivotally supports at 60, a downwardly extending vibrating presser 62 having a bifurcated foot 64, and a rearwardly extending lip 65, the vibrating presser being moveable between the arms of the bifurcated foot portion 42 of the presser foot 15. Carried by the forward end of the support member 36 is a leaf spring 66 which normally biases the vibrating presser 62 forwardly. Also carried by the support member 36 on the underface thereof and extending forwardly is a leaf spring 68 which bears upon the lower arm of an adjustable angular clip 70 mounted on the side of the angular lever 58, to normally bias the angular lever 58 upwardly. To provide clearance for the angular lever 58 relative to the screw 34 a portion of the lever 58 is cut away as In FIGS. 37 there are shown the relative positions of the I needle, the presser foot and the vibrating presser during a sew- FIG. 4 showing different additional positions of the attachment means during a sewing operation;

Referring to the several FIGS. of the drawing wherein corresponding parts are indicated by' the same reference numerals, I0 indicates the left end of a conventional drop-feed sewing machine head having a reciprocative needle bar 12 carrying a needle 13, a reciprocative presser foot bar 14 carrying a presser foot 15, the machine head being mounted on the table 16 provided with a throat plate 18 having openings 20 through which a feed dog 22 is operative.

Mounted on the needle bar 12 is a clamp 24 having a laterally extending cylindrical pin 26, the function for which will presently appear.

The presser foot bar 14 at its lower end is formed with a rectangular shank 28 which engages in a groove 30 formed in the presser foot 15, and is locked in said groove by a screw 34. The presser foot I5 has a rearwardly projecting support member 36 having opposite flat faces 38 and 40/ and a downwardly extending bifurcated foot portion 42. The support member 36 has mounted on the top thereof a bifurcated stud 44 in which is pivoted a lever 46 having adjacent its rear end a transversely extending cam follower 47.

Pivotally mounted on a screw 48 adjacent the rear end of the support member 36 and moveableover the face 38 of said support member is a cam lever 50 having a cam surface 52 adjacent its rear end and at its forward end having a slot 54 within which is slidable the pin 26 on the clamp 24 carried by the needle bar I2. The arrangement is such that when the neeing operatiomAs will be apparent from FIGS. 3 and-4, when the needle is in its uppermost position, the presserfoot 15 is out of engagement with the workpieces, (notshown) the cam has acted on the cam follower to cause the lever 46 to depress on' the angular lever 58 to move the foot 64 of the vibrating presser into engagement'with the workpieces and the feed dog 22 is in positionto move the vibrating presser and the work- .pieces rearwardly the length of a stitch and tension the springs 66 and 68 and while this is being done the presser foot portion 62 moves into engagement with the workpieces. As the needle penetrates theworkpieces, (FIG. 5) the cam follower leaves the cam andthe spring 68-raises the angular lever 58 while the spring 66 kicks said lever forwardly as shown in FIG. 6. As the needle again moves upwardly, (FIG. 7) the cam follower again rides on the cam, the vibrating presser is again moved into engagement with the workpieces and the presser foot rises out of engagement with the workpieces to repeat the cycle of forming the next stitch.

It will thus be appreciated that the workpieces are at all times held firmly in superimposed relationship and that they are simultaneously moved forwardly against relative move ment therebetween by the cooperation of the feed dog and the vibrating presser to insure against puckering ofthe workpieces while being sewed.

1 claim: I

1. Top feed attachment means for use on a drop-feed sewing machine having a reciprocative needle bar carrying a needle, a reciprocative presser foot bar and a feed dog operative through a throat plate to engage the underface of the bottom of one of a plurality ofsuperimposed workpieces to advance said workpieces along a feed path, said attachment means comprising a support member adapted to be fixedly mounted on the presser foot bar and provided with a presser foot, a first lever pivotally mounted on the support member rearwardly of the presser foot, a vibrating presser pivotally carriedby said lever and moveable into and out of engagement with the workpieces alternately to the movement of the needle bar, a cam lever pivotally carried by the support member, means on the cam lever engageable with the needle bar for oscillating the cam lever as the needle bar is reciprocated, a second lever pivotally mounted on the support member and havingone'end thereof contacting the'first lever and the other end having a cam follower operable by the cam lever for moving the first lever and the vibrating presser into engagement with the workpieces, first spring means biasing the first lever and the vibrating presser for moving the vibrating presser out ofengagement with the workpieces when the cam follower means is not being acted upon by the cam lever, second spring means biasing the vibrating presser forwardly when the vibrating presser is out of engagement with the workpieces. and wherein the support member has opposite flat faces on which the first lever and the port member.

2. Feed attachment means according to claim 1 wherein the second lever overlies and traverses the support member. 

1. Top feed attachment means for use on a drop-feed sewing machine having a reciprocative needle bar carrying a needle, a reciprocative presser foot bar and a feed dog operative through a throat plate to engage the underface of the bottom of one of a plurality of superimposed workpieces to advance said wOrkpieces along a feed path, said attachment means comprising a support member adapted to be fixedly mounted on the presser foot bar and provided with a presser foot, a first lever pivotally mounted on the support member rearwardly of the presser foot, a vibrating presser pivotally carried by said lever and moveable into and out of engagement with the workpieces alternately to the movement of the needle bar, a cam lever pivotally carried by the support member, means on the cam lever engageable with the needle bar for oscillating the cam lever as the needle bar is reciprocated, a second lever pivotally mounted on the support member and having one end thereof contacting the first lever and the other end having a cam follower operable by the cam lever for moving the first lever and the vibrating presser into engagement with the workpieces, first spring means biasing the first lever and the vibrating presser for moving the vibrating presser out of engagement with the workpieces when the cam follower means is not being acted upon by the cam lever, second spring means biasing the vibrating presser forwardly when the vibrating presser is out of engagement with the workpieces and wherein the support member has opposite flat faces on which the first lever and the cam lever respectively are coaxially pivotally mounted and the second lever is pivotally mounted on a stud fixed on the support member.
 2. Feed attachment means according to claim 1 wherein the second lever overlies and traverses the support member. 